Sensibly equivalent¶ to:
This exhibit is a Tungsram 5Z4G full wave rectifier. The white paint lettering came away during a light dusting.
Professional equipment, including radar, etc., sometimes required circuits in which valve cathodes carried large signals and had to 'float' at voltages well below that of the chassis. Glass-envelope '-G' versions of common types were therefore required. The original metal envelope 5Z4 had to have the outer envelope at below cathode potential to prevent them acting as an anode so were at a disadvantage in these applications.
Initially, these '-G' versions were larger than their metal counterparts but with the introduction of 'pinchless', slimline '-GT' types 5Z4GT the advantage of the compact metal types was reduced to the point where RCA decided to phase out production in favour of (slightly cheaper) all-glass types.
Designed to supply equipment of up to 40 Watts total power, this rectifier was made by several manufacturers. This suggests a very popular type, and one that found use in military equipment during WWII.
Each anode is a folded sheet that has an enclosed cylindrical space at one end and a side flange for support and extra surface area for heat radiation.
A closer view of the electrodes. The indentations in the anode add extra strength and resistance to buckling.
The classic envelope is 45 mm in diameter and, excluding the IO base pins, is 99 mm tall.
References: Data-sheet & 1043. Type 5Z4G was first introduced in 1940.
Absolute Maximum Operating Conditions¶
Updated January 12, 2016.